Governorships: D 29 R 21. A VERY good year for Democrats; voters are less partisan in gubernatorial elections than in congressional elections, so states that would never elect a Dem for Senate (e.g. Wyoming) have Democratic governors and states where Republicans are in trouble (e.g. Rhode Island) are going to reelect R governors by wide margins.
(NOTE AFTER ELECTION: I got this almost 100% right; the only govenror's race I missed was Minnesota, where a R gov won 51-49 instead of losing 51-49 as I expected).
Senate: R 52 D 48 A few days ago I thought this would be 50-50 at worst for the Dems. But the Dems only have two guaranteed gains (Ohio, Pa).
Five more seats are more or less tossups- Montana, RI, Virginia and Missouri (all with R incumbents), Maryland (D open seat). I think the Dems only win two of the five- if I had to guess, holding Maryland and winning one of the four GOP seats.
(AFTER ELECTION NOTE: Of course, the Dems won all five! I thought that there would be a Republican surge that didn't happen; the same explains my error re the House, where the Dems look like they will have around 230).
House- 219 D 216 R. I think the Rs are closing fast and usually perform better than polls suggest in House races (for a wide variety of reasons). I think the chances of the Ds winning the House are still slightly better than 50-50 (but only slightly, and only because a bunch of R seats are in trouble due to scandals).